燃焼合成法によるNi－Al-Si系金属間化合物の作製とそのコーティングへの応用

摘要

Nickel aluminide based intermetallic compounds as a surface layer on spheroidal graphite cast iron substrate (FCD 450) were combustion synthesized from a powder mixture of elemental Ni, Al and Si powders. With a composition of Ni-78 at percent (Al-8 at percent Si), Al_3Ni and Al_6Ni_3Si were formed mainly by hot pressing. Densification of the compact was enhanced with increasing the eutectic Al-Si ratio in the precursor powders. Al-Si eutectic liquid phase infiltrated well into the boundary of each particle, which also reacted with the substrate to form intermetallic reaction layers. These layers were formed on both sides of the coating layer and FCD substrate, and the constituent phases were identified as Al_7Fe_2Si, FeAl_3 respectively. The interface of reaction layers of 10 mu m were chemically well-bonded.